Printed Circuit Board Connector

Abstract

In a printed circuit board connector, a resilient latching tang is positioned on an inner wall of the connector block housing and is movable relative thereto into latching relationship with a terminal having a plurality of contacts for resiliently engaging a circuit board, the resilient latching tang being movable into and out of latching engagement with the terminal independently of the engagement of the contacts with the circuit board.

Parent Case Text

This is a continuation of application Ser. No. 97,906, filed Dec. 14, 1970 and now abandoned.

Description

BACKGROUND AND SUMMARY OF THE INVENTION

This invention relates to a new and improved printed circuit board connector and terminal construction.

Connector blocks have been employed in the past for receiving a plurality of terminals and positioning the terminals for resilient engagement with a circuit board which is also received in the connector block. In many of these prior arrangements, no means is provided for positively latching the terminal in the connector block other than by friction and the terminals of these embodiments are thereby susceptible to inadvertent separation from the terminal block and circuit board during use. In order to prevent such accidental separation, several embodiments of connector arrangements have incorporated a resilient latching construction as part of the terminal which is adapted to be movable so as to grasp a fixed rigid latching shoulder or abutment on the connector block housing in order to prevent terminal separation from the connector block. Since these circuit board connector terminals are frequently quite small, these movable latching mechanisms are usually formed as an integral part of the terminal and the circuit board contact engaging structure of the terminal in a one-piece construction. Consequently, these terminals are latched against removal from their connector block, but if removal of the terminal is actually desired while the circuit board is present, such removal may be accomplished only with some difficulty, since the resilient circuit board contact engaging structure resists unlatching of the terminal. Moreover, if it is desired to insert a terminal in a connector block in which the circuit board is present, such insertion is also resisted, since the circuit board contact engaging structure prematurely urges the latching mechanism toward the latching position. Thus, in the prior circuit board connector block and terminal constructions in which a resilient movable latching mechanism is formed on the terminal, insertion and removal of the terminal is not only impaired when a circuit board is present in the connector block, but stresses and wear are imparted to the terminal which reduce the mechanical life of the terminal.

In the circuit board connector of the present invention, latching and unlatching of the terminal from the connector block housing is accomplished independently of circuit board contact structure of the terminal and thereby the effect of the presence of the circuit board in the block is substantially reduced if not eliminated altogether. Moreover, in the present invention at least one point of contact between the terminal and circuit board is assured at all times, even if the circuit board or circuit board contacts are dirty. The connector constructed in accordance with the principles of the invention is extremely simple in design and inexpensive to manufacture and the terminal of the invention may be formed as a simple one-piece stamping.

In one principal aspect of the invention, a printed circuit board connector assembly includes a connector block housing having a cavity therein opening through one side of the housing for receiving at least one terminal, a terminal having resilient contact means for engaging a conductive surface on the circuit board and circuit board positioning means for positioning the circuit board in contact with the terminal contact means. Resilient latching means is mounted on a wall of the cavity and is movable relative to the wall and independently of the engagement of the contact means with the circuit board to latchingly engage the terminal for locking the terminal against axial movement out of the cavity.

In another aspect of the invention, a terminal for use with a circuit board includes a U-shaped planar portion having a pair of elongate electrically conductive legs extending in spaced relationship to each other, an electrically conductive web on at least one of the legs and extending substantially perpendicular to the U-shaped planar portion and from the edge of the leg closest to the other leg, and electrically conductive resilient circuit board contact means is mounted on the web. Latching means is positioned on the web for locking the terminal in a connector block independently of the engagement of the circuit board contact means with the circuit board.

These and other objects, features and advantages of the present invention will become apparent upon a consideration of the following detailed description.

BRIEF DESCRIPTION OF THE DRAWING

Reference will frequently be made hereafter to the attached drawing in which:

FIG. 1 is an exploded isometric view of a connector block, circuit board and terminal assembly incorporating the principles of the invention;

FIG. 2 is an end elevation view of the assembly of the invention showing the terminal and connector block in assembled relationship and taken substantially along line 2 -- 2 of FIG. 1;

FIG. 3 is a plan view of the assembly of the invention in which a portion of the connector block has been cut away as indicated substantially along line 3 -- 3 of FIG. 2; and

FIG. 4 is an enlarged cross sectioned elevation view of the assembly of the invention taken substantially along line 4 -- 4 of FIG. 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A preferred embodiment of connector block and terminal assembly which is constructed in accordance with the principles of the invention is shown in FIG. 1. The assembly includes a connector block housing 10 which is adapted to receive a plurality of terminals 12 through one end 14 thereof. The circuit board 16, upon which a plurality of conventional conductive strips 18 are carried on at least one side thereof, is adapted to be received through the opposite end 20 of the housing 10.

The terminal 12 may be stamped or otherwise suitably formed of brass, steel or other conductive material and comprises a flat U-shaped planar portion 22 having a pair of elongate legs 23 and 24 extending in substantially parallel spaced relationship to each other from the bight 25 of the U. Extending from the opposite side of the bight 25, is a suitable conductor connector portion 26 having one or more tabs 28 which are adapted to be bent over and firmly receive the conductive end 30 of a suitable conductor wire 32 as shown in the drawing.

In order to establish electrical connection between the U-shaped planar portion 22 and the conductive strips 18 on the circuit board 16, resilient contact clip members 33 and 34 are formed integrally from each of the legs 23 and 24, respectively. Each clip member includes a web 36 preferably formed in integral relationship with its leg by bending the web from the inner leg edge such that the web 36 is substantially perpendicular to the plane of the U-shaped portion 22. A pair of resilient curved circuit board contact surfaces 37 and 38 are then bent from each end of the web 36 of each member 33 and 34. The contact surfaces 37 and 38 of the respective clip members are spaced from each other by a distance such that they will receive the thickness of the circuit board 16 therebetween in resilient clamping and contacting relationship with the board 16. A recess or opening 40 is formed in one or both of the webs 36 which forms part of the terminal latching construction as will be described in more detail to follow.

Turning to the construction of the connector block 10, the connector block comprises a generally elongate rectangular housing 42 having an enlarged rectangular cavity 44 moulded therein. The housing 42 is preferably moulded of an insulative material, such as a phenolic resin or nylon. The cavity 44 is divided into a plurality of passages 46, 47, 48 and 49 which extend from end 14 to end 20 of the connector block and which are adapted each to receive one of the terminals 12 therein. The passages are defined by way of top and bottom walls 51 and 52 of the housing cavity 44 and are separated from each other by side partition walls 53 which extend at least part of the way through the length of the passages and between the top wall 51 and bottom wall 52.

An elongate rib 54 is also formed on the top and bottom walls 51 and 52 of each passage, preferably by way of being integrally moulded in the housing. This rib extends in thickness toward the axis of each passage and is of a width somewhat less than the width of each passage, as defined by the distance between its side walls 53, so as to define guide channels 56 adjacent the top and bottom walls and extending over the length of the passage between the rib 54 and the side walls 53 of each passage. The width of the guide slots 56 is substantially equal to the thickness of the U-shaped planar portion 22 of the terminals and the distance between the top wall and bottom wall of the passage is substantially equal to the distance between the outermost edges of the legs 23 and 24 of the U-shaped planar portion such that the terminal is insertable in an edgewise manner as shown in FIGS. 2 - 4 into the passage and is firmly maintained against lateral movement in upper and lower ones of the guide slots.

A resilient latching tang 58 is also formed upon at least one of the walls of each passage and extends downward from the top wall rib 54 into each of the passages. The latching tangs 58 are preferably also moulded in integral one-piece relationship with the connector block housing 42. The end of the latching tang 58 opposite its end of attachment 60 to the housing, includes a projecting latching structure 61 having an inclined portion 62 which gradually inclines toward the axis of the passage and a latching shoulder 64 which extends at a sharp angle to the passage axis. In addition, the latching structure 61 preferably includes an upwardly inclined unlocking surface 66 which is adapted to receive a suitable unlocking tool 68 for disengaging the latching structure from the terminal, as will be described in more detail later.

The end 20 of the connector block housing opposite the terminal insertion end 14, is formed with a laterally extending elongate slot 70 which is of a size and shape to receive a similarly sized and shaped circuit board 16 for insertion into the housing. Additional openings 72 are also formed through the end 20 of the housing between the wall upon which the resilient tangs 58 are carried and the slot 70 to allow insertion of the unlocking tool 68 as shown in FIG. 4.

Assembly and disassembly of the circuit board connector block and terminal assembly of the invention will now be described.

One or more terminals 12 are first inserted into one or more of the respective passages 46, 47, 48 and 49 through the open end 14 of the connector block housing 42. To insert a terminal 12, the terminal is first oriented such that its U-shaped planar portion 22 is positioned on edge and spans the distance between the top and bottom walls 51 and 52 and is positioned in alignment with the upper and lower guide slots 56 adjacent one of the passage side walls 53. The leading end of terminal 12 is then positioned in the bottom and top slots 56 and is slid forward and to the right as viewed in FIG. 4, into the passage 47 until the leading ends of the terminal legs 23 and 24 engage vertical stops 74 integrally molded in the ends of the passages adjacent the slot side 20 of the housing. The inner periphery of slot 70 of the housing 42 is also preferably turned in at 76 adjacent slot 70 so as to generally conform with the curvature of the leading contact surfaces 37 as shown in FIG. 4. Thus, when the terminal 12 has been fully inserted in its passage, the leading end of the contact surfaces 37 will also engage the inner wall end of the housing end 20.

As the terminal 12 is inserted into the passage, at one point the leading end of the upper web 36 will contact the incline 62 of the latching structure 61 and, upon further insertion, the resilient tang 58 and its latching structure will be urged upward as viewed in FIG. 4 toward the top wall 51 of the passage 47. Finally, when the terminal has been fully inserted into the housing, the latching shoulder 64 of the projecting latching structure 61 will drop into the opening 40 in web 36 and will engage the leading edge of the opening to prevent removal of the terminal from the housing as shown in FIG. 4.

When one or more of the terminals 12 have been positioned in the connector block housing, the circuit board 16 may be inserted through the slot 70 from the right as viewed in FIG. 4. When the circuit board 16 has been fully inserted into the housing 42, its leading edge 78 will come to rest against the bight 25 of the terminal and the board will be firmly clamped between the upper and lower contact surfaces 37 and 38 of the clip members 33 and 34, and the upper contact surfaces 37 and 38 will resiliently and firmly engage selective ones of the conductive strips 18 on the circuit board, depending upon which passages terminals have been inserted. An electrical circuit will thereby be established between the conductor wire 32, the U-shaped planar portion 22 of each terminal, the upper web 36, and both upper contact surfaces 37 and 38 to the respective conductive strips 18 on the circuit board. It will be seen that both upper contact surfaces 37 and 38 will contact a given conductive strip 18. Thus, uninterrupted contact will be insured between the terminal and the circuit board even in the event that one of the contact surfaces or the conductive strip is dirty. In fact, if the strip 18 is dirty, the leading contact surface 37 will tend to wipe the strip to insure that the trailing surface 38 will make clean contact.

It will be seen when considering the above description, that the terminal 12 is capable of insertion with equal facility into any one of the passages when the terminal is oriented either as shown in the drawing or upside down. If the terminal is reversed, the lower clip member 34 will become the upper and will perform the same circuit board engaging and contacting function previously described with respect to clip member 33 and the planar portion 22 will be positioned in the other of the guide slots 56 in the passage. Moreover, it will also be seen that additional terminals may be readily inserted into the housing 42 after the circuit board has been positioned in the housing and that these terminals will be latched independently of their contact with the circuit board by way of the resilient latching tang 58.

If it is now desired to remove one or more of the terminals, whether or not the circuit board is presently positioned in the block housing 42, such removal may be easily effected independently of the engagement of the contact surfaces 37 and 38 with the circuit board simply by the insertion of tool 68 through the proper opening 72 so as to engage the unlatching surface 66 of the resilient tang 58. When the tool is so engaged, the tang and its latching structure 61 may be easily pried upward without moving the contact surfaces 37 and 38 and the terminal may be pulled out of the passage to the left as viewed in FIG. 4. Thus, frequent insertion, removal and rearrangement of the terminals is facilitated independently of and without regard to the presence or absence of a circuit board in the connector block and damage and wear to the respective terminals 12 is substantially reduced.

It will be understood that although the assembly shown in the drawings includes only four passages, the number of passages, as well as the number of terminals which may be inserted into the connector block 10, may be varied as desired. Moreover, it will be understood that the embodiment of the invention which has been described is merely illustrative of one application of the principles of the invention. Numerous modifications may be made by those skilled in the art without departing from the true spirit and scope of the invention.

Claims

1. In a printed circuit board connector assembly including a connector block housing defining a cavity therein which opens through one side of the housing for receiving at least one terminal, said terminal having resilient contact means for flexibly engaging a conductive surface on the circuit board and circuit board positioning means on the housing for positioning the circuit board in contact with the contact means, wherein the improvement comprises in combination therewith:

resilient latching means mounted on a wall of said cavity and movable relative to said wall independently of the engagement of said contact means with said circuit board to latchingly engage said resilient contact means for locking said terminal against axial movement of the terminal out of said cavity, said terminal being movable relative to said cavity independently of the engagement of said terminal contact means and circuit board conductive surface, said resilient contact means comprising a pair of resilient contact surfaces spaced from each other in a direction parallel to the direction of movement of said terminal, and a web connecting said contact surfaces, said latching means being positioned to

2. In the assembly of claim 1 wherein said resilient latching means includes a resilient tang in said cavity having an inclined portion for engaging said terminal when said terminal is being inserted in said cavity to urge said tang toward said cavity wall and a latching portion for latchingly engaging said terminal when said terminal is fully inserted in

3. In the assembly of claim 1 wherein said resilient latching means includes a resilient tang having a latching portion for engaging said terminal when said terminal is fully inserted in said cavity and unlatching means for disengaging said latching portion from said terminal.

4. In the assembly of claim 1 wherein said resilient latching means includes a resilient tang having a projecting latching portion thereon and said terminal includes a recess for receiving said projecting latching

5. In a printed circuit board connector assembly comprising:

a housing defining a plurality of passages therein opening through one side of the housing, each of said passages having top and bottom walls and at least one side wall,

a terminal positioned in at least some of said passages comprising a U-shaped planar portion having a pair of legs, the width of said U-shaped planar portion being substantially equal to the distance between the top and bottom walls of said passages,

an elongate slot at said top and bottom walls adjacent at least one of said side walls for receiving at least one of the legs of said U-shaped planar portion therein,

an elongate opening in said housing for insertion of a circuit board into said passages,

resilient contact means on at least one of the legs of said U-shaped planar portion for engaging said circuit board when the board is inserted into a passage, and

resilient latching means mounted on one of said top and bottom walls for movement relative to its wall and positioned to latchingly engage said contact means for locking said terminal against movement from its passage independently of the engagement of said contact means with said circuit

6. In the assembly of claim 5 including unlatching means for unlatching said latching means independently of the engagement of said contact means

7. A terminal which is adapted to be connected to a circuit board comprising:

a U-shaped planar portion having a pair of elongate electrically conductive legs extending in spaced substantially parallel relationship to each other,

a web on at least one of said legs extending substantially perpendicular to said U-shaped planar portion and from adjacent the edge of said leg closest to the other leg,

resilient circuit board contact means extending from said web, and adapted to engage the circuit board, said resilient contact means and said web being electrically conductive, and

latching means on said web for locking said terminal in a connector block independently of the engagement of said resilient circuit board contact

8. The terminal of claim 7 including a web and resilient circuit board contact means on both of said legs, the circuit board contact means of each said leg being spaced from each other by a distance so as to receive the circuit board therebetween and resiliently engage the circuit board.

9. The terminal of claim 8 wherein both of said resilient contact means and

10. The terminal of claim 7 wherein said electrically conductive circuit board contact means comprise a pair of longitudinally spaced contact

11. The terminal of claim 7 wherein said latching means comprises a recess in said web which is adapted to receive a resilient latching member therein.